Primes of the form 2*3^k - 1.A079363Primes of the form 2*3^k - 1.Terms a(0) =5a(1) =17a(2) =53a(3) =4373a(4) =13121a(5) =1062881a(6) =6973568801a(7) =188286357653External referencesoeis: A079363